[helm] Add the force_update arg (#509)

[helm] Add the force_update arg

Depends-On: ansible/ansible-zuul-jobs#1648
Depends-On: #522
SUMMARY
Sometimes a Helm repo needs to be updated with a new URL. The helm repo add command allows for this with the --force-update flag:
      --force-update               replace (overwrite) the repo if it already exists


ISSUE TYPE

Feature Pull Request - Closes #491

COMPONENT NAME
kubernetes.core.helm_repository
ADDITIONAL INFORMATION

Reviewed-by: Mor Cohen <morcohen1201@gmail.com>
Reviewed-by: Mike Graves <mgraves@redhat.com>

tests/integration/targets/helm/tasks/tests_repository.yml

@@ -42,6 +42,19 @@
     that:
       - repository_errors is failed
 
+- name: Succesfully add repository with the same name when forcing
+  helm_repository:
+    binary_path: "{{ helm_binary }}"
+    name: test_helm_repo
+    repo_url: "{{ chart_test_repo }}"
+    force: true
+  register: repository
+
+- name: Assert that test_helm_repo repository is changed
+  assert:
+    that:
+      - repository is changed
+
 - name: Remove test_helm_repo chart repository
   helm_repository:
     binary_path: "{{ helm_binary }}"